The other thing is that you need to be playing on a Pangea style map.
A continents, arcipeligo, or any map that has ocean tiles segregating you from the AI will make the AI extremely passive. Sure, they'll declare war on you for no reason. In fact, all the AI will probably declare war on you all at once for no reason. But they wont ever cross over the water to go attack you.
I just played a game on this True Start Locations map on deity. I knew what to expect, so basically I just pumped out crossbows/xbowmen waiting for the AI's close to me to gang up on me. Fended them off, then countered and razed stuff til they declared peace, the terms of which I would ask for lots of money or resources. I'd buy some units with it and kill off another sap, he'd declare peace, I'd get more resources... repeat. Once I controlled my region of the map, the AI's on the different continents just took eachother out, asked for assistance, declared war on me (but never actually attacked me as I was across the ocean). I just swooped in and sniped the capital cities and got domination victory.
I've found that a lot of the time it's better to just damage an enemy AI unit on the front lines than to actually kill it, just leave it there to heal up and block his buddies from coming through. The damaged units wont attack.
I used to get worried when a bunch of AI would try to surround me, now it's quite easy to figure out what they're going to do and you can just outlast them with your fortification bonuses. The honor tree and things that give you combat bonuses for fighting in friendly territory are especially useful.
Autosaves are great, if the AI suddenly bum rushes you and takes you out unexpectedly, don't get frustrated, try loading an autosave ~10 - 20 turns back and figure out what you did wrong and what you need to do to survive. This is how I got better quickly.
On Deity, your happiness can dip extremely low very quickly. This could be a problem depending on your playstyle, but in the short term it doesn't really matter -- you just want to turtle up and take out the AI's attacking forces as safely as possible.
Ok, so, TL;DR.. if you think it's too easy, play a pangea map. I've found large to be the most interesting. Epic speed feels about right to me as well. Try it on a higher difficulty. Make sure you know what the AI has units wise. You can assume the AI is going to attack you once they get some units at your borders and start talking
<snip> to you.=)
Alright, that's enough rambling, it's late -- so I hope that was coherent. If someone needs help with a specific game toss over a save file..
Moderator Action: Swearing is not allowed on these forums, thanks.
Please read the forum rules: http://forums.civfanatics.com/showthread.php?t=422889